RFID —radio frequency identification— is a means of identifying objects via a wireless communication protocol, a capability that enables myriad advantages and breakthroughs in applications ranging from supply chain management to asset tracking to authentication of frequently counterfeited pharmaceuticals.
Some have likened RFID to an electronic barcode, which is an oversimplification. RFID technology goes far beyond the capability of passive, non-unique printed graphics (barcodes) that require line-of-sight to readers, lack interactivity, cannot be used to identify unique objects, and are easily counterfeited or otherwise compromised. RFID tags are sophisticated, intelligent devices that carry unique, field-updatable information. They leverage huge efficiencies not only in time, cost, and labor, but in unprecedented supply chain visibility. These are just a few of the reasons driving major retailers, the Department of Defense, the FDA, and other organizations and entities to mandate the deployment of RFID technology.
A typical RFID system consists of three primary components: tags, readers, and reader antennas. Let’s take a closer look at each of these components.
The reader, also known as an interrogator, is a device that provides network connectivity between tag data and enterprise system software. The reader communicates with the RFID tags within its field of operation, performing any number of operations including simple continuous inventorying, filtering (searching for tags that meet certain criteria), writing to selected tags, etc.
The reader uses its antenna to send information encoded in a modulated waveform as well as the tone that the tag uses to power itself. A receiver circuit on the tag is able to detect the modulated field, decode the information, and use its own antenna to send (backscatter) a response.
RFID Reader Antennas
Reader antennas, like tag antennas, may also assume form factors appropriate to their application. For example, antennas may be fitted to dock doors, embedded in store shelves or racks, fitted within a point-of-sale terminal, or integrated into the guide rails of conveyor equipment.
RFID Tag Manufacturing
An RFID tag generally comprises an integrated circuit (IC or chip) that has been mounted on a flexible PET (PolyEthyleneTherephtalate) or paper substrate, which has been preprinted with conductive ink (or assembled with an etched, stamped, or vapor-deposited antenna pattern), according to the particular antenna design. The resulting inlay assembly is then converted or sandwiched between a printed label and its adhesive backing, yielding a smart label. This label can be programmed with a unique tracking identifier called an electronic product code (EPC) and attached to an item, case, or pallet. For some applications, tag chips can also be factory programmed before they are assembled.